Desktop far image read-write device with contrast control

Abstract

The utility model discloses a desktop remote image read-write device with contrast control. The desktop remote image read-write device comprises a plane spectroscope, a concave reflector and a backlight plate. The light reflected by the desktop and an object placed on the desktop is emitted to the plane spectroscope from the lower part, and the light split by the plane spectroscope is reflected by the concave reflector, is split by the plane spectroscope again, is emitted to an exit pupil position, and forms a far image at a position not less than 1 meter; brightness of different areas of the backlight plate is different so as to change contrast of different areas of a far image. According to the desktop far image read-write device, when a user reads characters and other contents in a book, the peripheral low-contrast visual effect is provided, the growth of an eye axis is further inhibited, meanwhile, a certain effect is achieved on thickening of a choroid, and myopia prevention and control are achieved.

Description

TECHNICAL FIELD

[0001] The utility model relates to a desktop far image reading and writing equipment with contrast control belongs to myopia prevention and control equipment field. BACKGROUND

[0002] At present, the myopia problem of teenagers is increasingly serious, the fundamental reason is that the eyes of teenagers focus on the near range most of the time, the eye axis gradually lengthens to adapt to close-up imaging. In order to solve this problem, various myopia prevention and control products have emerged in the market.

[0003] Among them, the desktop far image reading and writing equipment is a device that uses optical means to image the close-up reading and writing to a distance, and is mainly used in the field of myopia prevention and control of teenagers. However, the effect of single light path on myopia prevention and control is limited, therefore, other auxiliary means need to be introduced to increase the effect of myopia prevention and control. SUMMARY

[0004] The technical problem to be solved by the utility model is to provide a desktop far image reading and writing equipment with contrast control.

[0005] In order to realize the above technical purpose, the utility model adopts the following technical scheme:

[0006] A desktop far image reading and writing equipment with contrast control comprises a plane beam splitter, a concave mirror and a backlight plate, wherein,

[0007] The concave mirror is kept in a horizontal or vertical position in the use state, and the plane beam splitter is inclined in the use state.

[0008] The backlight plate is arranged perpendicular to the concave mirror, and is used to provide light to the exit pupil position.

[0009] The light reflected by the desktop and the object placed on the desktop is shot to the plane beam splitter from below, and the light formed after the light is split by the concave mirror is reflected by the concave mirror, then the light is split by the plane beam splitter, and is shot to the exit pupil position, and forms a far image at a position not less than 1 meter. Different regions of the backlight plate provide at least two kinds of light with different brightness to the exit pupil position, wherein the brightness of the first kind of light is lower than that of the second kind of light, so as to change the contrast of different regions of the far image.

[0010] Preferably, the ratio of the brightness of the second kind of light provided by the backlight plate to the average brightness of the far image is not less than 1 / 9.

[0011] Preferably, the ratio of the brightness of the first kind of light provided by the backlight plate to the average brightness of the far image is less than 1 / 10.

[0012] As a preferred embodiment, the backlight panel is provided with active light-emitting elements on the surface facing the exit pupil position, and the first light and the second light are provided to the exit pupil position in different regions by controlling the brightness of the active light-emitting elements in different regions.

[0013] Preferably, the desktop telephoto read-write device further comprises an eye movement tracking camera and a controller.

[0014] The eye movement tracking camera is arranged to face the exit pupil position and is used to collect human eye images.

[0015] The controller determines the gaze point of the human eye in the telephoto image according to the human eye image, and makes the brightness of the gaze area in the backlight panel centered on the gaze point lower than that of the surrounding area of the gaze area.

[0016] Preferably, the active light-emitting element is an array light source, and the array light source covers the entire area of the backlight panel. The controller makes the light source in the gaze area low in brightness or not emit light.

[0017] Preferably, the active light-emitting element comprises a fixed white board and a dark electrochromic film covering it. The transmittance of the electrochromic film at different positions at different times is controlled by a logic timing circuit to change the brightness of different regions of the backlight panel.

[0018] Preferably, the active light-emitting element is a display screen, and the brightness of different regions of the backlight panel is changed by controlling the display of different position pixels in the display screen.

[0019] Preferably, the active light-emitting element is an array light source, and the array light source is only distributed in the peripheral region of the backlight panel or only in one or more local regions.

[0020] As another preferred embodiment, the backlight panel provides the at least two different brightness light rays to the exit pupil position by reflection.

[0021] Preferably, the reflectivity of the central region of the backlight panel is less than 5%, and the peripheral region of the backlight panel around the central region has at least one region with a reflectivity not less than 5%.

[0022] Preferably, the surface of the backlight panel is provided with a first region and a second region, wherein at least one of the material, color or surface microstructure of the first region and the second region is different, so that the second region has a higher reflectivity than the first region.

[0023] Preferably, the second region of the backlight panel has an array of convex points or an array of concave points.

[0024] Preferably, the desktop telephoto reading and writing device further comprises a light source assembly for providing a light source to the backlight plate; the surface of the backlight plate has the same reflectivity, and the light source assembly irradiates a local area of the backlight plate to reflect the second light to the exit pupil position through the local area of the backlight plate.

[0025] Preferably, the light source assembly comprises a light source and a mask.

[0026] Preferably, the mask is a diffractive optical element.

[0027] Preferably, the desktop telephoto reading and writing device further comprises a first adjusting member for adjusting the included angle between the plane beam splitter and the concave mirror and keeping the plane beam splitter at at least two positions with the included angle between the plane beam splitter and the concave mirror being between 30° and 60°; the height of the exit pupil position relative to the desktop is changed by adjusting the included angle between the plane beam splitter and the concave mirror through the first adjusting member.

[0028] Preferably, the desktop telephoto reading and writing device further comprises a light supplementing lamp arranged on the lower surface of the plane beam splitter, and the light supplementing lamp is composed of a plurality of light sources arranged in a linear array, the plurality of light sources are arranged in a stepped manner, and the chief rays of the light sources are perpendicular to the desktop when the plane beam splitter and the desktop form an angle of 45° in the use state.

[0029] The desktop telephoto reading and writing device with contrast control provided by the present application uses a coaxial optical system to image the reflected light of the desktop and the object placed on the desktop, meanwhile, the backlight plate is added, and the backlight plate provides light with different brightness to the exit pupil position in different areas, so as to change the contrast of different areas of the telephoto, and the purpose of myopia prevention and control is achieved. The desktop telephoto reading and writing device with contrast control introduces the contrast control while forming the telephoto, when the user reads the content such as the text in the book, the visual effect of low contrast is given to the periphery at the same time, the retinal stimulation is reduced, the growth of the eye axis is further inhibited, and the thickening of the choroid is also affected to a certain extent, and the purpose of myopia prevention and control is achieved. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 is a structural schematic view of the desktop telephoto reading and writing device with contrast control provided by the embodiment 1 of the present application;

[0031] Figure 2 is Figure 1 is a schematic view of the light path principle of the horizontal exit pupil of the desktop telephoto reading and writing device shown in

[0032] Figure 3A and Figure 3B is Figure 1 is a schematic view of the light path principle of the two kinds of inclined exit pupils of the desktop telephoto reading and writing device shown in

[0033] Figure 4 is the schematic diagram of the adjusting structure of the desktop far-field read-write equipment shown in embodiment 1;

[0034] Figure 5 is Figure 1 the schematic diagram of the arrangement mode of the middle array light source;

[0035] Figure 6 is the structural schematic diagram of the desktop far-field read-write equipment with a low contrast in a peripheral area provided by the embodiment 2 of the present application;

[0036] Figure 7 is the structural schematic diagram of the desktop far-field read-write equipment with contrast control provided by the embodiment 3 of the present application;

[0037] Figure 8 is Figure 7 the schematic diagram of the optical path principle of the desktop far-field read-write equipment shown in the embodiment 1;

[0038] Figure 9A 、 Figure 9B 、 Figure 9C and Figure 9D are the schematic diagrams of the surface of the backlight plate respectively;

[0039] Figure 10A and Figure 10B are the structural schematic diagrams of the desktop far-field read-write equipment with contrast control provided by the embodiment 4 of the present application respectively;

[0040] Figure 11 is the structural schematic diagram of the desktop far-field read-write equipment with contrast control provided by the embodiment 5 of the present application. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0042] It should be noted that if the present application embodiments involve directional indications (such as up, down, left, right, front, back, …), the directional indications are only used to explain the relative position relationship, movement condition, etc. between the components in a certain specific posture (as shown in the drawings), if the specific posture changes, the directional indications also change accordingly.

[0043] In addition, if the description of "first", "second" and the like is involved in the embodiments of the present application, the description of "first", "second" and the like is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can be explicitly or implicitly included at least one of the features. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of ordinary skilled in the art, when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, and is not within the protection scope required by the present application.

[0044] The utility model aims at providing a kind of desktop telephoto reading and writing equipment with contrast control based on coaxial optical system implementation.The desktop telephoto reading and writing equipment with contrast control, it include: back light plate 3, plane beam splitter 1 and concave mirror 2;Wherein, one end of concave mirror 2 is connected with one end of back light plate 3, and it is kept in the position perpendicular to back light plate 3 in use state;Plane beam splitter 1 is obliquely arranged between concave mirror 2 and back light plate 3 in use state;Back light plate 3 side surface facing exit pupil is provided with active light emitting element (for example, array light source) or passive light emitting element, for providing light to exit pupil position.Light reflected by desktop 4 and object placed on desktop, from below to plane beam splitter 1, after light splitting of plane beam splitter 1, to concave mirror 2, then, after reflection of concave mirror 2, after light splitting of plane beam splitter 1, to exit pupil position, and telephoto is formed in position not less than 1 meter.Back light plate 3 side surface facing exit pupil is provided with active light emitting element or passive light emitting element, for providing light to exit pupil position;Different regions of the back light plate 3 provide at least two different brightness light to exit pupil position, wherein, the brightness of first light is lower than the brightness of second light, to change the contrast of the telephoto and the spot formed by the second light, so that different regions of telephoto have different contrast.

[0045] The change of the brightness of the second light to the contrast of the local area of the telephoto reduces the contrast of the local area of the telephoto to less than 90% of the original telephoto contrast, for example, to 30% to 90% of the original telephoto contrast. In order to meet the above contrast control, the brightness of the second light should meet the following conditions: the contrast of the original telephoto is defined as: Wherein, I max represents the maximum brightness of the telephoto, I min represents the minimum brightness of the telephoto, I 均 represents the average brightness of the telephoto, The brightness of the second light is defined as I, and the contrast of the local area coinciding with the spot in the telephoto is: Contrast’ <Contrast; To meet Then: That is, the ratio of the brightness I of the second light provided by the backlight panel 3 to the pupil position and the average brightness I of the teleimage is not less than 1 / 9. Preferably, it is lower than 7 / 3 or lower than 1. To reduce the influence of the first light actively or passively provided by the backlight panel 3 on the teleimage, the ratio of the brightness of the first light to the average brightness of the teleimage should be controlled below 1 / 10.

[0046] In the embodiments provided in this application, the positions of the backlight panel 3 and the concave mirror 2 can be interchanged. As Figure 1 shown, the backlight panel 3 can be vertically arranged at the top of the bracket 9. At this time, the concave mirror 2 is horizontally arranged in the use state. It can be understood that the backlight panel 3 can also be horizontally arranged in the use state, while the concave mirror 2 is vertically arranged at the top of the bracket. Since whether the positions of the backlight panel 3 and the concave mirror 2 are interchanged has no influence on the imaging principle of the fixed desktop teleimage reading and writing device, the positions of the backlight panel 3 and the concave mirror 2 are not limited herein. Hereinafter, a desktop teleimage reading and writing device in which the backlight panel 3 is vertically arranged at the top of the bracket 9 and the concave mirror 2 is horizontally arranged in the use state will be taken as an example for introduction.

[0047] Embodiment 1

[0048] As Figure 1 shown, a desktop teleimage reading and writing device with contrast control includes: a planar beam splitter 1, a concave mirror 2, a backlight panel 3 and a bracket 9; wherein, the bracket 9 is vertically arranged on the desktop 4, the backlight panel 3 is vertically arranged and connected to the top of the bracket 9; one end of the concave mirror 2 is connected to the top of the backlight panel 3 and remains in a position parallel to the desktop 4 in the use state; the top of the planar beam splitter 1 can rotate around the top of the backlight panel 3, and the planar beam splitter 1 is inclined and arranged between the concave mirror 2 and the backlight panel 3 in the use state. The light reflected by the desktop 4 and the object placed on the desktop is incident on the planar beam splitter 1 from below, passes through the planar beam splitter 1 and then is incident on the concave mirror 2 and is reflected at the position of the concave mirror 2; the light formed after being reflected by the concave mirror 2 is reflected by the planar beam splitter 1 and then is incident on the pupil position; the light incident on the pupil position forms a teleimage at a virtual image position not less than 1 meter in front of the pupil position.

[0049] In this desktop teleimage reading and writing device, a total reflection film is attached to the surface of the concave mirror 2 for imaging; the radius of curvature of the concave mirror 2 ranges from 800 mm to 1300 mm. The exit pupil distance of this desktop teleimage reading and writing device is between 150 mm and 350 mm, and the exit pupil eye movement range is not less than ​​The field of view is not less than 35° and not more than 50°.

[0050] Table 1 shows the surface parameters of a set of optical elements of the telecentric light path of the desktop telecentric read-write device.

[0051] Table 1 shows the surface parameters of a set of optical elements of the telecentric light path of the desktop telecentric read-write device.

[0052] Surface Mark Surface Type Radius (mm) Thickness (mm) Alpha Tilt (°) Image Surface Spherical Infinite -5000 0 Stop 5 Spherical Infinite 200 0 2 Spherical -1150 195 0 1 Spherical Infinite 345 -45 4 Spherical Infinite 0 -45

[0053] With the specific optical design shown in Table 1, the desktop telecentric read-write device with contrast control has an exit pupil distance of 200 mm, an exit pupil eye movement range of 20 mm, a lateral field of view of ± 19°, and a longitudinal field of view of ± 14°. The lateral field of view is ± 19°, and the longitudinal field of view is ± 14°.

[0054] To adapt to different height populations, the plane beam splitter 1 can also be rotated. By rotating the plane beam splitter 1, the direction of the light rays reflected by the plane beam splitter 1 towards the exit pupil position can be changed, the normal direction and height of the exit pupil position can be changed, and the height adjustment of the device can be avoided to change the virtual image position. As shown in Figure 2 , Figure 3A and 3B By changing the included angle γ between the plane beam splitter 1 and the concave mirror 2 (γ is between 30° and 60°), the height of the exit pupil position relative to the desktop can be adjusted.

[0055] As shown in Figure 2 , the plane beam splitter 1 is located at an angle of 45° to the horizontal line (desktop), at this time, the light rays reflected by the concave mirror 2 are reflected by the plane beam splitter 1 towards the exit pupil position 5 in a horizontal direction, at this time, the normal direction of the exit pupil position 5 is parallel to the desktop 4, this position corresponds to the horizontal exit pupil position, which can be used as the initial exit pupil position, at this time, the exit pupil plane is a vertical plane.

[0056] As shown in Figure 3A , by lifting the plane beam splitter 1 upwards, the included angle between the plane beam splitter 1 and the horizontal line is less than 45°, at this time, the light rays reflected by the concave mirror 2 are reflected by the plane beam splitter 1 towards the exit pupil position 6A in an oblique upward direction, at this time, the normal direction of the exit pupil position 6A forms an acute angle with the desktop, the line of sight of the person is slightly downward, the exit pupil position 6A is higher than the exit pupil position 5, the height of the exit pupil position relative to the desktop changes, and the exit pupil plane tilts relative to the horizontal plane and the vertical plane.

[0057] As shown in Figure 3BAs shown, by pressing down the plane beam splitter 1, the angle between the plane beam splitter 1 and the horizontal line is greater than 45°. At this time, the light rays formed after being reflected by the concave mirror 2 are reflected by the plane beam splitter 1 and then directed towards the exit pupil position 6B in a downward tilting direction. At this time, the normal direction of the exit pupil position 6B forms an acute angle with the table. The person's line of sight is slightly upward, and the exit pupil position 6B is lower than the exit pupil position 5. The exit pupil position has changed in height relative to the table, and the exit pupil plane has tilted relative to the horizontal and vertical planes.

[0058] It is understood that in this adjustable desktop image reading and writing device, the positions of the backlight panel and the concave reflector can be interchanged. The concave reflector is set vertically, and the backlight panel is set horizontally. The backlight panel is kept parallel to the desktop when in use. One end of the backlight panel is connected to the top of the concave reflector. The top of the planar beam splitter is connected to the backlight panel or the concave reflector and can rotate around the top of the concave reflector. The planar beam splitter is tilted between the concave reflector and the backlight panel when in use.

[0059] like Figure 4 As shown, in this desktop far-viewing reading and writing device, the tops of the backlight panel 3, the planar beam splitter 1, and the concave reflector 2 can be rotatably connected via one or two rotating shafts. To achieve angle adjustment of the planar beam splitter 1, the desktop far-viewing reading and writing device also includes a first adjusting member 13, which adjusts the angle between the planar beam splitter 1 and the concave reflector 2. One end of the first adjusting member 13 is connected to the planar beam splitter 1, and the other end is connected to the backlight panel 3 or the concave reflector 2. The first adjusting member 13 can be implemented using a rotating shaft with a limit mechanism, or it can be an independently installed adjusting member. For example, as... Figure 4 As shown, the angle between the planar beam splitter 1 and the concave mirror 2 is adjusted using a telescopic linkage.

[0060] The desktop telephoto reading and writing device can be a fixed device or a folding device. In the fixed device, the concave mirror 2 is always kept in a horizontal or vertical fixed state, and the concave mirror 2 is always perpendicular to the backlight plate 3. In the folding device, the concave mirror 2 and / or the backlight plate 3 can be rotated, so that the concave mirror 2 and the backlight plate 3 can be switched between a parallel state and a perpendicular state. When the concave mirror 2 and the backlight plate 3 are parallel to each other, it corresponds to the folding state of the desktop telephoto reading and writing device, i.e. the idle state. When the concave mirror 2 and the backlight plate 3 are perpendicular to each other, it corresponds to the opening state of the desktop telephoto reading and writing device, i.e. the use state. The above state transition can be realized by the second adjusting member 14, which is used to keep the concave mirror 2 in a parallel or perpendicular state with the backlight plate 3. It can be realized by a rotating shaft with a limiting mechanism, or it can be an independently arranged adjusting member. For example, the two ends of the second adjusting member 14 are connected with the backlight plate 3 and the concave mirror 2 respectively, and the state transition of the concave mirror 2 relative to the backlight plate 3 is realized by the second adjusting member 14.

[0061] In addition, it can be understood that when the first adjusting member 13 and the second adjusting member 14 are arranged at a position away from the top end of the concave mirror 2 and the plane light splitter 1, and only play a role of rotation adjustment and limiting, one or two rotating shafts need to be arranged between the plane light splitter 1, the concave mirror 2 and the backlight plate 3 to realize the connection between them. At this time, the rotating shaft can be a movable shaft that can rotate freely. When the first adjusting member 13 or the second adjusting member 14 is arranged at the end of the concave mirror 2 or the plane light splitter 1, the first adjusting member 13 or the second adjusting member 14 simultaneously plays a role of connection, rotation adjustment and limiting. At this time, the first adjusting member 13 or the second adjusting member 14 can only use a damping rotating shaft with a limiting mechanism to realize the above functions, and at this time, a movable shaft does not need to be additionally arranged.

[0062] As shown in Figure 1 The desktop telephoto reading and writing device provided by the utility model also has a contrast control function. A light-emitting element is arranged on the side of the backlight plate 3 facing the exit pupil, which is used to provide first light and second light with different brightness to the exit pupil in different areas. The brightness of the second light provided by the light-emitting element is higher than the brightness of the first light provided by other areas of the backlight plate 3, and the second light forms a light spot at the exit pupil, so as to reduce the contrast of the area where the telephoto image and the light spot coincide, thereby changing the contrast of different areas of the telephoto image and realizing contrast control.

[0063] In this embodiment, the light-emitting element includes an array light source 12. The light of the array light source 12 passes through the plane light splitter 1 and is emitted to the exit pupil. No matter when the exit pupil 5 is shown in Figure 2 or Figure 3A and Figure 3BAs shown at exit pupil positions 6A and 6B, when the human eye views a distant image, it can receive a second type of light emitted by the array light source. By controlling the brightness of different areas of the array light source, the contrast of different areas of the distant image can be changed.

[0064] Because the image size of desktop far-image reading and writing devices is relatively large, and the human eye's fixation point varies, it does not always converge at the center of the far image. Therefore, to improve the myopia prevention effect of contrast control, it is necessary to specifically control the brightness of local areas of the array light source. For this reason, such as... Figure 1 As shown, in this desktop far-viewing device, an eye-tracking camera 10 is also provided facing the human eye. For example, the eye-tracking camera 10 is provided on the upper surface of the planar beam splitter 1 or the front side facing the human eye when the concave reflector 2 is in use. The eye-tracking camera 10 is used to capture images of the human eye. The infrared light source in the eye-tracking camera 10 illuminates the eye and provides a corneal reflection point, while the high-speed camera captures photos to capture the movement of the human eye. Both the eye-tracking camera 10 and the array light source are electrically connected to the controller 8. The controller 8 obtains the gaze point of the human eye in the far-viewing image based on the human eye image, and makes the brightness of a small area centered on the gaze point in the array light source lower than the brightness of the surrounding area. The gaze area refers to this small area centered on the gaze point. The range of this gaze area needs to be determined in conjunction with the size of the area corresponding to the small field of view of the human eye on the backlight panel. It should not be larger than the size of the area corresponding to the ±15° field of view of the human eye in the array light source, and should not be smaller than the size of the area corresponding to the ±3° field of view of the human eye in the array light source. For example, the controller 8 receives and processes images captured by the eye-tracking camera 10, calculates the gaze position, analyzes the data, and then controls the light sources in the array light sources to emit light in areas other than the gaze area (e.g., a circular area centered on the gaze point with a diameter of 6 to 8 centimeters).

[0065] By controlling the brightness of the backlight panel, low contrast control is achieved in the area surrounding the fixation zone. This results in low or no light emission from the light source within the eye's fixation range and its surrounding small area, while the light source in other areas is brighter than that in the fixation zone. This creates a reduced contrast effect in the peripheral image of the focus area, which helps reduce the progression of myopia.

[0066] Lighting control for the gaze area can be achieved by reducing the brightness of the light source in the gaze area or turning off the light source in the gaze area. The brightness of the light sources in other peripheral areas of the array light source that are far from the gaze area can be the same as or lower than the brightness of the light sources in the surrounding areas of the gaze area; there are no restrictions here.

[0067] In this embodiment, the array light source can be an LED array, and the distribution pattern of the array light source can be referred to Figure 5As shown, the array light source can completely cover its entire area and be evenly distributed to cover the entire imaging range of the distant image. Thus, combined with eye tracking, targeted control of localized areas of the array light source can be achieved. To reduce the graininess of the array light source and minimize the impact of individual LEDs on image quality, a light-diffusing plate 11 is provided in the light-emitting direction of the array light source. Alternatively, the light-diffusing plate can be omitted, resulting in a dotted, low-contrast image around the viewing area.

[0068] like Figure 5 As shown, the LED array in the array light source can be distributed in a honeycomb pattern, with one LED at the center of each hexagon and a spacing of 5–15 mm between adjacent LEDs. The light-emitting surface is covered with a light-diffusing plate 11 to make the light softer. The LED array can also be arranged in other regular or irregular ways. In the exit pupil direction, a low-contrast image with high brightness backlight can be observed outside the non-fixated area, while the image within the fixed area is a high-contrast image with low brightness backlight or no backlight. By controlling the contrast of the surrounding image, the growth of the axial length of the eye is suppressed.

[0069] Contrast can also be achieved using different types of backlights. For example, a backlight can consist of a fixed white panel that emits light throughout and a dark electrochromic film covering it. The white panel can be mounted on the backlight, covered with a dark electrochromic film. A logic timing circuit can control the transmittance of the electrochromic film at different times and positions, thus changing the brightness of different areas of the backlight and creating a constantly changing contrast image at the human eye. Alternatively, a high-pixel-density display can be used to achieve the backlight. By controlling the display of pixels at different positions on the screen, the brightness of different areas of the backlight can be changed. By displaying different dot matrix images or other images on the screen, contrast control of local areas of the distant image can also be achieved, and the layout of the backlight's emitting area can be easily changed. The display on the backlight can also switch images to achieve vision training functions, including fixation training, fusion training, and near-far alternation training.

[0070] The desktop telephoto reading and writing device needs to be used in combination with the light supplement lamp 7. In order to ensure the brightness of the area below the plane beam splitter 1, the light supplement lamp 7 is arranged on the frame of the lower surface of the plane beam splitter 1. Preferably, the light supplement lamp is composed of a plurality of light sources arranged in a linear array. The plurality of light sources are arranged in a stepped manner. The plurality of light sources are arranged along the length direction of the plane beam splitter 1. In the use state in which the plane beam splitter 1 and the desktop form an angle of 45°, the chief rays of the light sources are vertically downward to the desktop. In order to meet the uniformity of the illumination of the desktop, the number of light sources distributed above can be more than the number of light sources distributed below, and the arrangement is dense. The light supplement lamp 7 is preferably arranged on the left and right frames of the lower surface of the plane beam splitter 1. The light supplement lamp 7 can also be arranged on the bottom frame of the plane beam splitter 1 and the bottom surface of the backlight plate 3 at the same time, for simultaneously providing light sources to the desktop.

[0071] The application also provides a control method of the desktop telephoto reading and writing device. The light reflected by the desktop 4 and the object placed on the desktop is downward to the plane beam splitter 1. The light split by the plane beam splitter 1 is to the concave mirror 2. Then, the light reflected by the concave mirror 2 is split by the plane beam splitter 1, and is to the exit pupil position. The telephoto image is formed at a position of not less than 1 meter. At the same time, the array light source is arranged to face the exit pupil position, and the brightness of different areas is different, so as to change the contrast of different areas of the telephoto image, and realize the contrast control.

[0072] As a preferred embodiment, the light emitting area of the array light source changes according to the position of the eye fixation point. The controller 8 obtains the eye fixation point in the telephoto image in real time according to the eye image, and makes the light source in a small range area of the array light source with the eye fixation point as the center have a lower brightness than the light source in the surrounding area. The eye fixation area refers to the small range area with the eye fixation point as the center. The size of the eye fixation area needs to be determined in combination with the area corresponding to the small field of view of the eye on the backlight plate. The size should be not greater than the size of the area corresponding to the ±15° field of view of the eye on the array light source, and not less than the size of the area corresponding to the ±3° field of view of the eye on the array light source. For example, the controller 8 receives and processes the picture taken by the eye tracking camera 10, calculates the fixation position, analyzes the data, and then controls the light source in the other areas of the array light source except the eye fixation area (for example, a circular area with a diameter of 6-8 cm with the eye fixation point as the center) to emit light, and makes the light source in the eye fixation area turn off. The light source brightness in the area outside the eye fixation area can be in a stepped increasing manner with the eye fixation point as the center. Of course, the controller 8 can also make the entire backlight plate have a gradually increasing brightness from the center outward with the eye fixation point as the center, so as to replace the above-mentioned on-off type brightness control. The ratio of the average brightness of the eye fixation area to the average brightness of the surrounding area should be lower than 40%.

[0073] By controlling the brightness of the backlight panel, low contrast is achieved in the area surrounding the fixation zone. This results in lower brightness in the eye's fixation area and surrounding small areas, while other areas are brighter than the fixation zone, creating a reduced contrast effect in the peripheral image of the focus area, which helps reduce myopia progression.

[0074] Example 2

[0075] like Figure 6 The illustrated embodiment provides a desktop far-image reading and writing device with contrast control, comprising: a planar beam splitter 1, a concave reflector 2, a backlight panel 3, and a bracket 9; wherein, the bracket 9 is vertically mounted on the desktop 4, the backlight panel 3 is vertically mounted and connected to the top of the bracket 9; one end of the concave reflector 2 is connected to the top of the backlight panel 3 and is held parallel to the desktop 4 in use; the top of the planar beam splitter 1 can rotate around the top of the backlight panel 3, and the planar beam splitter 1 is tilted between the concave reflector 2 and the backlight panel 3 in use. Light reflected from the desktop 4 and objects placed on the desktop is directed from below to the planar beam splitter 1, passes through the planar beam splitter 1, and is reflected at the position of the concave reflector 2; the light formed after being reflected by the concave reflector 2 is reflected by the planar beam splitter 1 and directed towards the exit pupil position; the light directed towards the exit pupil position forms a far image at a virtual image position not less than 1 meter in front of the exit pupil position.

[0076] In this embodiment, an active light-emitting element is provided on the side of the backlight panel 3 facing the exit pupil position. The active light-emitting element adopts an array light source 15, wherein the array light source 15 is distributed in a localized manner. For example, the array light source 15 is only provided in the peripheral area of ​​the backlight panel 3, thereby forming a light spot in the peripheral area of ​​the distant image to reduce the contrast of the area where the peripheral area of ​​the distant image coincides with the light spot, without changing the brightness and contrast of the central area of ​​the distant image.

[0077] The array light source can be symmetrically arranged on both sides of the backlight panel 3, or it can be arranged in the entire peripheral area of ​​the backlight panel 3, thus leaving a central area of ​​a circle, square or other symmetrical shape.

[0078] The array light source 15 can also be distributed in one or more local areas of the backlight plate 3. The arrangement of the local areas can be regular or irregular. Preferably, they are symmetrical about the center of the field of view or the axis of the field of view.

[0079] Furthermore, the backlight panel is replaceable, and by replacing the backlight panel, the distribution of contrast in the distant image can be changed, thereby changing the stimulation of the distant image on the human eye. The array light source is arranged differently in different backlight panels.

[0080] exist Figure 6In the embodiment shown, since the light source array in the backlight panel 15 is only arranged in the peripheral region, in this embodiment, the eye movement tracking sensor can not be arranged, and all the light sources in the peripheral region can be directly lit, the contrast ratio of the peripheral region of the far image is reduced, and the purpose of inhibiting the axial growth is achieved.

[0081] Embodiment 3

[0082] As Figure 7 shown, the desktop far image reading and writing device with contrast ratio control comprises a plane beam splitter 1, a concave mirror 2, a backlight panel 3 and a support 9; wherein the support 9 is vertically arranged on a desktop 4, the backlight panel 3 is vertically arranged and connected with the top end of the support 9; one end of the concave mirror 2 is connected with the top end of the backlight panel 3 and kept in a position parallel to the desktop 4 in the use state; the top of the plane beam splitter 1 can rotate around the top end of the backlight panel 3, and the plane beam splitter 1 is arranged between the concave mirror 2 and the backlight panel 3 in the use state; the light reflected from the desktop 4 and the object placed on the desktop is shot to the plane beam splitter 1 from below, and then is shot to the concave mirror 2 after being transmitted through the plane beam splitter 1 and is reflected at the position of the concave mirror 2; the light formed after being reflected by the concave mirror 2 is reflected by the plane beam splitter 1 and is shot to the exit pupil position; the light shot to the exit pupil position forms a far image at a virtual image position not less than 1 meter in front of the exit pupil position.

[0083] In the desktop far image reading and writing device, a total reflection film is attached to the surface of the concave mirror 2 used for imaging; the curvature radius of the concave mirror 2 is in the range of 800mm to 1300mm. The exit pupil distance of the desktop far image reading and writing device is between 150mm and 350mm, the exit pupil eye movement range is not less than the field of view angle is not less than 35° and not more than 50°.

[0084] As Figure 7 and Figure 8 shown, the desktop far image reading and writing device provided by the utility model also has the contrast ratio control function. In this embodiment, the surface of the backlight panel 3 facing the exit pupil position is non-mirror surface, which is used for providing at least two kinds of light with different brightness to the exit pupil position by reflection, wherein the first kind of light has lower brightness and the influence on the brightness of the far image can be ignored, and the second kind of light has higher brightness and can form a light spot in different regions of the far image, so as to reduce the contrast ratio of the region where the far image and the light spot coincide, thereby realizing the contrast ratio control of different regions of the far image.

[0085] The brightness of the second kind of light provided to the exit pupil position by the backlight panel 3 should be not less than 1 / 9 of the average brightness of the far image, and the purpose of reducing the contrast ratio of the local region of the far image is achieved, for example, the contrast ratio of the local region of the far image is reduced to 30% to 90% of the original contrast ratio.

[0086] The reflection of the backlight plate 3 can be achieved by setting the surface of the backlight plate 3 facing the exit pupil side as different regions and making them have different reflectivity. Among them, the surface reflectivity of at least part of the region is greater than 5%, which is used to reflect the second light and form a light spot at the exit pupil position to reduce the contrast of the area where the far image coincides with the light spot; the surface reflectivity of the remaining part of the region is less than 5% to absorb and as far as possible to reduce the reflected light, so that the influence of the first light on the far image can be ignored.

[0087] As shown in Figure 7 , as a preferred implementation, the reflectivity of the central region of the backlight plate 3 is less than 5%, and the peripheral region around the central region has at least one region with a reflectivity of not less than 5%, which is called the second region. In addition to the second region, the other regions (including the central region and the remaining part of the peripheral region excluding the second region) constitute the first region. In this way, the second light is formed by the reflection of the second region, and the second light forms a light spot at the exit pupil position to reduce the contrast of the area where the far image coincides with the light spot, achieving the purpose of peripheral contrast control.

[0088] The reflection of the second region of the backlight plate 3 is not limited to the peripheral reflection mode as shown in the figure. The surface of the backlight plate 3 can be regularly or irregularly provided with a first region and a plurality of second regions, wherein the first region is the region of the surface of the backlight plate 3 excluding the second region, and any one of the material, color or structure of the first region and the second region is different, so that the second region has a higher reflectivity than the first region.

[0089] For example, Figure 9A through Figure 9D As shown in the figure, the peripheral region of the surface of the backlight plate 3 facing the exit pupil side is distributed with several second regions capable of providing scattering effect, which is approximately Lambertian scattering with a reflectivity of 5% to 10%. The second region reflects the received light into the human eye. The light received by the second region is not limited to the light produced after the light reflected by the desktop is split by the plane beam splitter, but can also be the light directly reflected from the desktop to the backlight plate 3 or the light directly irradiated to the backlight plate 3 by the supplementary light. Regardless of the part of the light reflected by the second region of the backlight plate 3 and shot at the exit pupil position, a light spot can be formed. The non-scattering region of the backlight plate 3 is the first region. The texture of the non-scattering region is fine, for example, using black frosted or black light-absorbing material, the glare and scattered light is very small, greatly reducing the influence on the far image.

[0090] The scattering region of the backlight plate 3 can change the size of the scattered light by different roughness of the texture (see Figure 9A ) and the shape of the texture (see Figure 9B ), and also by the color of the scattering region (see Figure 9DThe scattering light intensity can also be changed by changing the color and texture of the scattering area at the same time, thereby affecting the degree of change of the peripheral contrast. Figure 9A - Figure 9D In the embodiment, the texture roughness of the scattering area is between VDI 27 and VDI 40, and the internal texture of the scattering area can be ordered or random. In different backlights 3, the distribution of the second area can also be different, as shown in Figure 9A 、 Figure 9C and Figure 9D , although the second area is distributed in the peripheral area of the backlight 3, the size and distribution of the second area are different in different backlights.

[0091] Specifically, in Figure 9A - Figure 9D , except that there is no scattering area in the central area (300 mm in length and 130-170 mm in width) of the backlight 3, various scattering area patterns can be regularly or irregularly distributed in other areas, the spacing between patterns is d, and the maximum size of the pattern is a, then a>4mm, d≥0.3a. Figure 9B Compared with Figure 9A , the texture of the scattering area is changed to increase the surface roughness of the second area; Figure 9C Compared with Figure 9A , the distribution and number of scattering areas are different; Figure 9D and Figure 9A 、 Figure 9B 、 Figure 9C Compared with, not only the texture of the scattering area is different, but also the contrast of the far image peripheral area is changed by changing the color of the scattering area.

[0092] Embodiment 4

[0093] The desktop far image reading and writing device with contrast control as shown in Figure 10A and Figure 10B , comprising: a plane beam splitter 1, a concave mirror 2, a backlight 3 and a support 9; wherein the support 9 is vertically arranged on a desktop 4, the backlight 3 is vertically arranged and connected with the top end of the support 9; one end of the concave mirror 2 is connected with the top end of the backlight 3 and is kept in a position parallel to the desktop 4 in use; the top of the plane beam splitter 1 can rotate around the top end of the backlight 3, and the plane beam splitter 1 is inclinedly arranged between the concave mirror 2 and the backlight 3 in use, the light reflected after passing through the desktop 4 and the object placed on the desktop is shot to the plane beam splitter 1 from below, and then shot to the concave mirror 2 and reflected at the position of the concave mirror 2 after passing through the plane beam splitter 1; the light formed after being reflected by the concave mirror 2 is reflected by the plane beam splitter 1 and shot to the exit pupil position; the light shot to the exit pupil position forms a far image at a virtual image position not less than 1 meter in front of the exit pupil position.

[0094] In this embodiment, as shown in Figure 10AAs shown in the figure, a pit array 17 is arranged on the surface of the backlight panel 3 facing the exit pupil position, realizing the partial reflection of the backlight panel 3. When the pit area reflects the light, the pit area forms the second light through the reflection, and the second light to the exit pupil position forms a light spot. The contrast of the area where the far image and the light spot overlap decreases. By changing the reflectivity and distribution of the scattering area, the brightness and display position of the above-mentioned light spot can be changed, thereby regulating the contrast and layout of the far image.

[0095] Similarly, as shown in the figure, Figure 10B A convex array 18 is arranged on the surface of the backlight panel 3 facing the exit pupil position, realizing the partial reflection of the backlight panel 3. When the convex area reflects the light, the convex area forms the second light through the scattering, and the second light to the exit pupil position forms a light spot. The contrast of the area where the far image and the light spot overlap decreases. By changing the reflectivity and distribution of the scattering area, the brightness and display position of the above-mentioned light spot can be changed, thereby regulating the contrast and layout of the far image.

[0096] Example 5

[0097] As shown in the figure, Figure 11 The desktop far image reading and writing device with contrast control includes a plane beam splitter 1, a concave mirror 2, a backlight panel 3, and a support 9. The support 9 is vertically arranged on a desktop 4, and the backlight panel 3 is vertically arranged and connected with the top end of the support 9. One end of the concave mirror 2 is connected with the top end of the backlight panel 3 and is kept in a position parallel to the desktop 4 in the use state. The top of the plane beam splitter 1 can rotate around the top end of the backlight panel 3, and the plane beam splitter 1 is arranged between the concave mirror 2 and the backlight panel 3 in the use state. The light reflected by the object placed on the desktop 4 through the desktop 4 is incident on the plane beam splitter 1 from below, and then is reflected by the plane beam splitter 1 and the concave mirror 2. The light formed after being reflected by the concave mirror 2 is reflected by the plane beam splitter 1 and then is incident on the exit pupil position. The light incident on the exit pupil position forms a far image at a virtual image position not less than 1 meter in front of the exit pupil position.

[0098] As shown in the figure, Figure 11 By increasing an additional light source on the lower surface of the plane beam splitter 1, the light source provides illumination to different areas of the backlight panel 3. By means of the reflection of the partial area of the backlight panel 3, a light spot is formed to reduce the contrast of the area where the far image and the light spot overlap.

[0099] As shown in the figure, Figure 11 The surface of the backlight panel 3 facing the exit pupil position is non-specular and has the same reflectivity (preferably between 3% and 8%). In combination with the light source assembly arranged opposite to the backlight panel 3, the light source assembly irradiates the partial area of the backlight panel, so as to reflect the light to the exit pupil position through the partial area of the backlight panel, thereby realizing the effect of reducing the contrast of the partial area of the far image.

[0100] The light source assembly comprises a light source and a mask, which can be a diffractive optical element. The shape and intensity of light are regulated by installing a DOE module 20 composed of a micro laser and a diffractive optical element (DOE) in a groove under the plane mirror 1, so that the light is shot onto the backlight 3 to form different layouts of light spots or lines, so that the layout is more diversified. Its optical path is shown in Figure 11 The light hitting the backlight 3 is scattered by the backlight 3 and directly incident on the human eye through the plane mirror 1, thereby reducing the contrast of the far image corresponding position.

[0101] In order to fully utilize the contrast control bonus period, the position of the light spot can be changed periodically, for example, by periodically replacing different backlights 3 or periodically changing the light source signal directed to the backlight 3, to achieve the above purpose.

[0102] In summary, the desktop far image reading and writing device with contrast control provided by the present application uses a birdbath coaxial optical system to magnify and project the objects such as books placed on the desktop, and realizes the imaging effect similar to a zoom lens. This structure can obtain almost no distortion and high definition picture without introducing a free curved surface, and reduces the difficulty of processing and adjustment. Moreover, the desktop far image reading and writing device simultaneously introduces contrast control, which reduces the contrast of the picture outside the gaze area when the user reads the text and other contents in the book, reduces the stimulation of the retina, inhibits the growth of the eye axis, and may have a certain effect on the thickening of the choroid, thereby realizing myopia prevention and control.

[0103] The desktop far image reading and writing device with contrast control provided by the present application is described in detail above. For those skilled in the art, any obvious modification made to it without departing from the essential content of the present application will constitute an infringement of the patent right of the present application, and will bear the corresponding legal responsibility.

Claims

1. A desktop far-field read-write apparatus with contrast control, characterized by, It comprises: a plane beam splitter, a concave mirror and a backlight panel; wherein, the concave mirror is kept in a horizontal or vertical position in the state of use; the plane beam splitter is arranged in an inclined manner in the state of use; the backlight panel is arranged perpendicularly to the concave mirror, and is used to provide light to the exit pupil position; the light reflected by the desktop and the objects placed on the desktop is emitted to the plane beam splitter from below, and the light formed after the light is split by the concave mirror is reflected by the concave mirror, then split by the plane beam splitter, and finally emitted to the exit pupil position and forms a far image at a position of not less than 1 meter; different regions of the backlight panel provide at least two kinds of light with different brightness to the exit pupil position, wherein the brightness of the first kind of light is lower than that of the second kind of light, so as to change the contrast of different regions of the far image.

2. The desktop far image reading and writing device according to claim 1, wherein: the ratio of the brightness of the second kind of light provided by the backlight panel to the average brightness of the far image is not less than 1 / 9.

3. The desktop far image reading and writing device according to claim 1, wherein: the ratio of the brightness of the first kind of light provided by the backlight panel to the average brightness of the far image is less than 1 / 10.

4. The desktop far image reading and writing device according to claim 1, wherein: a side surface of the backlight panel facing the exit pupil position is provided with an active light emitting element, and the first kind of light and the second kind of light are provided to the exit pupil position in a region-by-region manner by controlling the brightness of different regions of the active light emitting element.

5. The desktop far-field read-write apparatus of claim 4 wherein It further comprises an eye movement tracking camera and a controller; the eye movement tracking camera is arranged to face the exit pupil position and is used to collect human eye images; the controller is used to determine the fixation point of the human eye in the far image according to the human eye images, and to make the brightness of a fixation region of the backlight panel centered on the fixation point lower than that of the surrounding region of the fixation region.

6. The desktop far image reading and writing device according to claim 5, wherein: the active light emitting element is an array light source, and the array light source covers the entire region of the backlight panel; the controller makes the light source of the fixation region low in brightness or not emit light.

7. The desktop far image reading and writing device according to claim 5, wherein: the active light emitting element comprises a fixed white plate and a dark electrochromic film covering the fixed white plate; the transmittance of the electrochromic film at different positions at different times is controlled by a logic timing circuit, so as to change the brightness of different regions of the backlight panel.

8. The desktop far image reading and writing device according to claim 5, wherein: the active light emitting element is a display screen; the brightness of different regions of the backlight panel is changed by controlling the display of different positions of the display screen.

9. The desktop far image reading and writing device according to claim 4, wherein: the active light emitting element is an array light source; the array light source is only distributed in the peripheral region of the backlight panel or only in one or more local regions.

10. The desktop far image reading and writing device according to claim 1, wherein: the backlight panel provides the at least two kinds of light with different brightness to the exit pupil position in a region-by-region manner through reflection.

11. The desktop far image reading and writing device according to claim 10, wherein: The reflectivity of the central region of the backlight plate is less than 5%, and the peripheral region of the backlight plate around the central region has at least one region with a reflectivity of not less than 5%.

12. The desktop telecentric read-write device of claim 10, wherein: The surface of the backlight plate is provided with a first region and a second region, wherein at least one of the material, color or surface microstructure of the first region and the second region is different, so that the second region has a higher reflectivity than the first region.

13. The desktop telecentric read-write device of claim 12, wherein: The microstructure of the second region of the backlight plate is an array of convex points or an array of concave pits.

14. The desktop far-field read-write apparatus of claim 10, wherein Further comprising: A light source assembly for providing a light source to the backlight plate; the surface of the backlight plate has the same reflectivity, and the light source assembly irradiates a local region of the backlight plate to reflect the second kind of light to the exit pupil position through the local region of the backlight plate.

15. The desktop telecentric read-write device of claim 14, wherein: The light source assembly includes a light source and a mask.

16. The desktop telecentric read-write device of claim 15, wherein: The mask is a diffractive optical element.

17. The desktop far field read-write apparatus of claim 1 wherein, Further comprising: A first adjusting member for adjusting the included angle between the plane beam splitter and the concave mirror and keeping the plane beam splitter at at least two positions with the included angle between the plane beam splitter and the concave mirror being between 30° and 60°; by adjusting the included angle between the plane beam splitter and the concave mirror through the first adjusting member, the height of the exit pupil position relative to the desktop is changed.

18. The desktop far field read-write apparatus of claim 1 wherein Further comprising: A supplementary light lamp arranged on the lower surface of the plane beam splitter, the supplementary light lamp is composed of a plurality of light sources arranged in a linear array, the plurality of light sources are arranged in a stepped manner, and in the use state that the plane beam splitter and the desktop form an angle of 45°, the chief rays of the light sources are perpendicular to the desktop.

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